Apparatus for drying laundry



B. DALL'O Nov. 15, 1966 APPARATUS FOR DRYING LAUNDRY 3 Sheets-Sheet 1 Filed March 31, 1965 ATTORNEYS Nov. 15, 1966 B. DALLO 3, 8 ,916

APPARATUS FOR DRYING LAUNDRY Filed March 51, 1965 5 sheets sheet 2 INVENTOR BEA/JAM/Al 441. '0

ATTORNEY' United States Patent Ollice 3,2843% Patented Nov. 15, 1966 3,284,916 APPARATUS FOR DRYING LAUNDRY Benjamin Dallt), Lessingstrasse 9, Zurich, Switzerland Filed Mar. 31, 1965, Ser. No. 444,335

9 Claims. (Cl. 34-15) This invention relates to an installation or apparatus for drying laundry, and more particularly it relates to such an installation in which the drying is accomplished by circulating heated air at a pressure less than atmospheric pressure.

Known laundry or wash driers formed as mobile units have the disadvantage that when used in drying rooms as mobile or also as stand units, they are as a rule spaced too far from the floor and let pass warm air streams to the outside. These mobile laundry driers further are not sufficient enough when used in conventional drying rooms, as a window of the drying room has to be opened entirely or partly for the purpose of letting escape the moist air, which again causes the drying room to cool too much and thus brings about an extension of the drying time. When using two drying rooms, which is necessary for a more voluminous wash, either two driers have to be available or the total wash has to be dried in succession in one or both rooms, which may require more than a day with the relatively excessive drying time.

The present invention avoids the aforesaid disadvantages and may be briefly described as comprising, in combination, a Wallchest-like housing, a timer-controlled recirculation fan, heating means, a waste-air fan, electric circuit means including said recirculation and said waste-air fans, and a switching apparatus adapted to automatically control the switching operations.

Details of the invention, as well as improvements and advantages effected by it, will be apparent from the following description in conjunction with the accompanying drawings, in which:

FIG. 1 is a front elevation of the vacuum warm-air unit;

FIG. 2 is a vertical longitudinal section through same, on the line HII of FIG. 1;

FIG. 3 is a plan of the drying room in which is positioned said warm-air uni-t;

FIG. 4 shows a portion of the drying room of FIG. 3 seen from the side;

FIG. 5 is a side view of the drying room including said warm-air unit and showing a modification of the device for hanging the wash, and

FIG. 6 is a plan pertaining to FIG. 5.

The vacuum warm-air drier shown in FIGS. 1 and 2 comprises a fiat box-like housing 1 of the dimensions 1 ft. by 2 ft.-4 inches in plan and 5 ft. in height, for example. To the rearwall of housing 1 is secured a wallframe 2 that is secured to the wall 23 of a drying room 24 (FIG. 3) by stone studs 4, resilient bumpers 3 being interposed between housing 1 and wall 23. The lower portion of housing 1 is conically tapered downwardly, as seen from the side. The housing is provided with a downwardly pointing air-inlet 5 that extends across the entire width thereof and that is provided with a wire-mesh 5'. The housing front wall is provided with a warm-air outlet 6 on top, that is covered by a wire-mesh 6. An air-duct 7 extending within said housing, being adjacent to the housing rearwall and connected thereto, is provided with an electric heating unit 8 and with a pipe coil 9 as an additional heating means, said coil being connectable to the central heating system (not shown). To air duct 7 is connected a twin turbine 11 driven by a motor 10. Air-duct 7 on top is connected to air-outlet 6 through a 90-bend.

Between duct 7 and the front box-wall is disposed a connection-box 12 for accommodating the wiring for the switch means. The latter are mounted on the rearside of a frontsheet 14 which is inserted in a holding frame 13 of the housing front-wall, and comprise a timer 15 and switching keys 16 to 18. The latter in connection with thermostats 19, 20 and through the two first keys 16, 17 permit a stepwise heating of 104 F. for woolen laundry and 167 F. for normal wash. When actuating the third key 18 and turning off the electric heating unit 8, permits to dry with the aid of non-heated air or air heated solely by the heating coil 9.

The warm-air drier further is provided with a waste-air pipe 21 that is disposed in housing 1 besides air-duct 7 and connected to a small turbine 22 that is driven by a separate motor 22'. That end of pipe 21 which leaves housing 1 leads through wall 23 of drying room 24 to the outside or into any adjacent room. Through fan 22, 22' a portion of the moist air entering through the bottom into housing 1 is moved to the outside or out of the drying room.

The driving and switching elements arranged in housing 1 may be made readily accessible by forming the housing 1 in two parts, for example by connecting the part serving as rearwall to the housing front-portion by means of hinges 1.

The warm-air drier described, as shown in FIGS. 3 and 4, is combined with a drying room 24 specially built for this purpose and having a base of about square feet area. The window or door 28 thereof are closable as airtight as possible, and clotheslines 25 at a height of about six feet are stretched from one holder 26 to the next holder 27 at spacings of about six inches so that the warm air may pass between the wash. In contrast to FIG. 3, housing 1 with the assemblies disposed therein could be mounted in the upper portion of the drying room, instead of in the intermediate portion thereof.

When setting the laundry drier to Work, first the twin turbine and the electric heating unit 8 is started through the timer. After the room temperature has been raised to the upper limit set by the keys 16 and 17, fan 22, 22 is switched on by the response of the respective thermo stat 19, 2t). Thereby a substantial portion of the moist recirculating air flowing into housing 1 at the bottom thereof, will be removed and thus a constant subpressure produced in the drying room, which substantially accelerates evaporation of the moisture present in the wash. By virtue of the vacuum drying process, the drying time is surprisingly shortened both when drying with the aid of Warm air and with cold air.

In the vacuum-type warm-air drying layout shown in FIGS. 5 and 6, the holders 26, 27 which comprise pieces of tubing, are pivoted to a pipe piece 29 that serves as axle. Pipe piece 29 at one end is secured to wall 23, and at its other end to the opposite wall. Axle pipe 29 of the two holders 26, 27 is positioned approximately at the elevation of outlet 6. The angle of tilt of the two holders 26, 27 is limited by a stop 30 that is disposed at least on one of the two Walls. In the horizontal position of the two holders 26, 27 all the clotheslines 25 are at the same elevation. This position is preferred for hanging the wash 31.

In the tilted position of the holders 26, 27 the holderends facing the warm-air unit 1 are situated below outlet 6, so that when setting the plant to work the airstream sweeps the plane formed by the clothesline under an acute angle and reaches all the spaces between the lines in 0 which equal partial streams a in the intermediate wash spaces are downwardly deflected.

This arrangement of the clotheslines permits an uni- 3 form air distribution on to all the wash 31 when the holders have been tilted to the inclined position.

With the aid of the apparatus according to the invention, it is possible to dry the entire monthly wash of a family of five persons in three to six hours in a well closed room of approximately 95 to 105 square feet. Such performance permits the builder of an apartment house for, say, 20 families to incorporate a single room of 105 square feet area in lieu of two such rooms of 215 to 270 square feet, as is conventional.

The device or respectively the warm-air drier may be arranged both with pipe coils for central-heating connection and with a heating system adapted for operation by electric energy, or with both said heating systems for both types of heating. As in the two first cases it also is possible to operate with only one heating system or with cold air only, heating costs may be reduced as desired,

depending on the time available for drying.

While the invention has been described in detail with respect to a now preferred example and embodiment of the invention it will be understood by those skilled in the art after understanding the invention, that various changes and modifications may be made without departing from the spirit and scope of the invention and it is intended, therefore, to cover all such changes and modifications in the appended claims.

Having thus described my invention, I claim as new and desire to secure by Letters Patent 1. An installation for drying laundry comprising in combination a wallchest-like housing, a timer-controlled recirculation fan disposed in said housing in a duct provided with heating means, the air-inlet of said duct being situated on the housing underside and the air-outlet being situated on the housing topside above the laundry to be dried, further comprising a waste-air fan in said housing having an air-inlet on its underside and an air-outlet leading outside, electric circuit means including said recirculation and said waste-air fans, and a switching apparatus adapted to automatically control the switching operations.

2. An installation for drying laundry comprising in combination a wallchest-like housing, a timer-controlled recirculation fan disposed in said housing in a duct provided with heating means, the air-inlet of said duct being situated on the housing underside and the air-outlet being situated on the housing topside above the laundry to be dried, further comprising a waste-air fan in said housing having an air-inlet on its underside and an air-outlet leading outside, electric circuit means including said recirculating and said waste-air fans, and a switching apparatus adapted to automatically control the switching operations, an air heater is provided in said housing in the airstreamrange of said recirculating fan, said heater including said air-inlet below and said air-outlet on top, and a waste-air pipe line disposed in the range of said waste-air fan and running out of the drying-room and being provided with the air-outlet, the switching means for the heating system and the fans being pre-adjustable by said timer to be cut-in and out automatically after setting in operation the installation.

3. An installation for drying laundry comprising in combination a wallchest-like housing, a timer-controlled recirculation fan disposed in said housing in a duct provided with heating means, the air-inlet of said duct being situated on the housing underside and the air-outlet being situated on the housing topside above the laundry to be dried, further comprising a waste-air fan in said housing having an air-inlet on its underside and an air-outlet leading outside, electric circuit means including said recirculating and said waste-air fans, and a switching apparatus adapted to automatically control the switching operations, an air heater is provided in said housing in the airstream-range of said recirculating fan, said heater including said air-inlet below and said air-outlet on top, and a waste-air pipe line disposed in the range of said waste-air fan and running out of the drying-room and being provided with the air-outlet, the switching means for the heating system and the fans being pre-adjustable by said timer to be cut-in and out automatically after setting in operation the installation, a power-driven twin turbine is' provided for the air recirculation, said turbine 'being connected to the lower end of a duct disposed in said housing, said duct comprising the heating means.

4. An installation for drying laundry comprising in combination a wallchest-like housing, a timer-controlled recirculation fan disposed in said housing in a duct provided with heating means, the air-inlet of said duct being situated on the housing underside and the air-outlet being situated on the housing topside above the laundry, to be dried, further comprising a waste-air fan in said housing having an air-inlet on its underside and an air-outlet leading outside, electric circuit means including said recirculating and said waste-air fans, and a switching appara-,

tus adapted to automatically control the switching operations, an air heater is provided in said housing in the airstream-range of said recirculating fan, said heater including said air-inlet below and said air-outlet on top, and a waste-air pipe line disposed in the range of said waste-air fan and running out of the drying-room and being provided with the air-outlet, the switching means for the heating sysem and the fans being pre-adjustable by said timer to be cut-in and out automatically after setting in operation the installation, the air-duct incorporates as heating means a pipe coil for the central-heating connection and a heating element for operation through electric energy.

5. An installation for drying laundry comprising in combination a wallchest-like housing, a timer-controlled recirculation fan disposed in said housing in a duct provided with heating means, the air-inlet of said duct being situated on the housing under-side and the air-outlet being situated on the housing topside above the laundry to be dried, further comprising a Waste-air fan in said housing having an air-inlet on its underside and an air-outlet leading outside, electric circuit means including said recirculating and said waste-air fans, and a switching apparatus adapted to automatically control the switching operations, an air heater is provided in said housing in the airstream-range of said recirculating fan, said heater including said air-inlet below and said air-outlet on top, and a waste-air pipe line disposed in the range of said wasteair fan and running out of the drying-room and being provided with the air-outlet, the switching means for the heating system and the fans being pre-adjustable by said timer to be cut-in and out automatically after setting in operation the installation, a separate turbine and a separate motor are provided for generation of the waste-air stream in the waste-air line, and in which the turbine producing the waste-air stream is controlled by switching means that in turn are controlled by thermostate.

6. An installation for drying laundry comprising in combination a wallchest-like housing, a timer-controlled recirculation fan disposed in said housing in a duct provided with heating means, the air-inlet of said duct being s tuated on the housing underside and the air-outlet being situated on the housing topside above the laundry to be dried, further comprising a Waste-air fan in said housing having an air-inlet on its underside and an air-outlet leading outside, electric circuit means including said recirculating and said waste-air fans, and a switching apparatus adapted to automatically control the switching operations, an air heater is provided in said housing in the airstream-range of said recirculating fan, said heater includ- 1ng said air-inlet below and said air-outlet on top, and a waste-air pipe line disposed in the range of said Wasteair fan and running out of the drying-room and being provided with the air-outlet, the switching means for the heating system and the fans being pro-adjustable by said timer to be cut-in and out automatically after setting in operation the installation, the housing is made in two parts, comprising a rearwall and a removable frQnt part that serves as hood.

7. An installation for drying laundry comprising in combination a Wallchest-like housing, a timer-controlled recirculation fan disposed in said housing in a duct provided with heating means, the air-inlet of said duct being situated on the housing underside and the air-outlet being situated on the housing topside above the laundry to be dried, further comprising a waste-air fan in said housing having an air-inlet on its underside and an air-outlet leading outside, electric circuit means including said recirculating and said Waste-air fans, and a switching apparatus adapted to automatically control the switching operations, the clotheslines of the hanging device extend parallel to the direction of the airstream and are situated below the air-outlet.

8. An installation for drying laundry comprising in combination a wallchest-like housing, a timer-controlled recirculation fan disposed in said housing in a duct provided with heating means, the air-inlet of said duct being situated on the housing underside and the air-outlet being situated on the housing topside above the laundry to be dried, further comprising a waste-air fan in said housing having an air-inlet on its underside and an air-outlet leading outside, electric circuit means including said recirculating and said Waste-air fans, and a switching apparatus adapted to automatically control the switching operations, the clotheslines run transversely to the direction of the air-stream, and the clothesline-holders are pivoted to an axle lying at the elevation of the air-outlet, in such arrangement that when said holders are in the tilted position, the airstream sweeps the plane clotheslines under an acute angle.

9. An installation for drying laundry comprising in combination a wallchest-like housing, a timer-controlled recirculation fan disposed in said housing in a duct provided with heating means, the air-inlet of said duct being situated on the housing underside and the air-outlet being situated on the housing topside above the laundry to be dried, further comprising a waste-air fan in said housing having an air-inlet on its underside and an air-outlet lead ing outside, electric circuit means including said recirculating and said waste-air fans, a switching apparatus adapted to automatically control the switching operations, and tiltable clothesline holders pivoted to an axle lying at the elevation of the air-outlet, the angle of tilt of said clothesline holders being limited by at least one stop.

formed by the References Cited by the Examiner UNITED STATES PATENTS 1,328,897 1/1920 Rice 3415 1,527,192 2/1925 Judelson 34223 1,902,575 3/1933 Nichols 3415 2,441,730 5/1948 Strumia 34-5 2,907,117 10/1959 Parkinson 345 2,921,382 1/1960 Blurn 34223 3,096,164 7/1963 Stone 3448 WILLIAM J. WYE, Primary Examiner. 

1. AN INSTALLATION FOR DRYING LAUNDRY COMPRISING IN COMBINATION A WALLCHEST-LIKE HOUSING, A TIMER-CONTROLLED RECIRCULATION FAN DISPOSED IN SAID HOUSING IN A DUCT PROVIDED WITH HEATING MEANS, THE AIR-INLET OF SAID DUCT BEING SITUATED ON THE HOUSING UNDERSIDE AND THE AIR-OUTLET BEING SITUATED ON THE HOUSING TOPSIDE ABOVE THE LAUNDRY TO BE DRIED, FURTHER COMPRISING A WASTE-AIR FAN IN SAID HOUSING HAVING AN AIR-INLET ON ITS UNDERSIDE AND AN AIR-OUTLET LEADING OUTSIDE, ELECTRIC CIRCUIT MEANS INCLUDING SAID RECIRCULATION AND SAID WASTE-AIR FANS, AND A SWITCHING APPARATUS ADAPTED TO AUTOMATICALLY CONTROL THE SWITCHING OPERATIONS. 